The field of the invention is automated semiconducted wafer processing systems, used for processing semiconductor wafers, hard disk media, semiconductor substrates, optical media and similar materials requiring very low levels of contamination.
Computers, televisions, telephones and other electronic products contain large numbers of essential electronic semiconductor devices. To produce electronic products, hundreds or thousands of semiconductor devices are manufactured in a very small space, using lithography techniques on semiconductor substrates, such as on silicon wafers. Due to the extremely small dimensions involved in manufacturing semiconductor devices, contaminants on the semiconductor substrate material, such as particles of dust, dirt, paint, metal, etc. lead to defects in the end products.
To exclude contaminants, semiconductor substrates are processed within clean rooms. Clean rooms are enclosed areas or rooms within a semiconductor manufacturing facility, designed to keep out contaminants. All air provided to a clean room is typically highly filtered to prevent airborne contaminants from entering into or circulating within the clean room. Special materials and equipment are needed to maintain contaminants within the clean room at adequately low levels. Consequently, construction and maintenance of clean rooms can be time consuming and costly. As a result, the semiconductor processing equipment installed within a clean room should preferably be compact, so that large numbers of semiconductor wafers can be processed within a smaller space, thereby reducing space requirements and costs.
In the manufacturer of Semiconductor devices from wafers, or in the manufacture of similar flat substrate devices (such as wafers, disk media, optical media, etc., collectively referred to herein as xe2x80x9cwafersxe2x80x9d), it is often necessary or desirable to clean the wafers after certain processing steps. Cleaning is typically performed by rinsing and drying. Centrifugal rinser dryers have long been used for these types of cleaning steps. In centrifugal rinser dryers, the wafers are held within a rotor and spun at high speed, while sprayed with rinsing and drying liquids and/or gases. While centrifugal rinser dryers have been successfully used for many years, contamination of wafers can be even further improved, at least in some applications, by immersion processes.
However, immersion processes have their own engineering challenges. Immersion tanks typically require substantial space, which is disadvantages in a clean room environment. In addition, cross-contamination between liquids in adjacent tanks, or contamination of wafers by vapors of the liquids, must be minimized. Immersion processes and apparatus must also account for dripping of fluid off of the wafers, as they are moved between tanks. The inflow, maintenance, and draining of liquids must also be addressed, along with the handling of vapors generated from the liquids.
Accordingly, it is an object of the invention to provide an improved system for carrying out immersion processes in the manufacture of wafers and similar devices.
It is also an object of the invention to provide an improved immersion module subsystem.
It is a further object of the invention to provide improved immersion tank assemblies.
Other objects and advantages will appear. The invention resides not only in the systems described, but also in the subsystems and sub-combinations described and illustrated.
In a first aspect of the invention, an automated semiconductor processing system has an indexer or work in progress stocker module or section, and immersion module or section, and a processing module or section. A process robot is moveable between the sections. The immersion module is detached from the stocker and process modules, to avoid transmission of vibration to the immersion tanks in the immersion module.
In a second and separate aspect of the invention, immersion tanks within an immersion module are arranged in an offset radial pattern. As a result, the immersion module has a compact design requiring less floor space in a clean room environment.
In a third and separate aspect of the invention, an immersion robot is centrally positioned between immersion tanks, to facilitate movement of wafers between tanks reducing travel time and distances between tanks, and resulting in a compact design.
In a fourth and separate aspect of the invention, tank lids and controlled air flow help to control vapors generated by fluids in the tanks.
In a fifth and separate aspect of the invention, a quick dump rinse tank is provided for rinsing wafers, and then quickly dumping or removing the rinse fluid, providing reduced contamination levels.
Other advantages are described. The invention resides not only in the system, but also in the sub-systems and sub-assemblies described.